A hydraulic hammer, often referred to as a breaker, can be attached to various machines for the purpose of milling asphalt, concrete, stone, and other construction materials. A conventional hammer includes a work tool (e.g., a chisel) having a tip that engages the material to be milled, and a reciprocating piston that is moved by pressurized fluid to repetitively hit against a base end of the work tool. The piston is reciprocatingly disposed within a sleeve, and fluidly connected to a remote accumulator by way of passages formed in the sleeve.
An exemplary piston sleeve for a hydraulic hammer is disclosed in U.S. Patent Publication No. 2014/0262406 of Moore that published on Sep. 18, 2014 (“the '406 publication”). In particular, the '406 publication discloses a hammer having a metallic piston sleeve, in which a piston reciprocates, An iron sleeve liner is placed over the sleeve, and an accumulator membrane surrounds the sleeve liner. The piston is supplied with and drained of fluid by way of passages formed between the sleeve and the sleeve liner. Specifically, longitudinally extending slots are machined into an outer annular surface of the piston sleeve and, when the sleeve liner is placed over the piston sleeve, the slots become passages for transporting high-pressure fluid to and from the piston.
While the piston sleeve of the '406 publication may perform well in many applications, it may still be less than optimal. In particular, the piston sleeve and liner together weigh a considerable amount, and this weight may limit application of the associated hydraulic hammer to smaller machines. In addition, the fabrication of the sleeve, liner, and passages may be cumbersome and expensive.
The disclosed hammer and sleeve are directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.